More Wisdom From a Long-Ago Plague

In its own deadly way, the 1918 flu pandemic is the gift that keeps on giving. It’s hard to say anything good about a global scourge that claimed 50 million lives, but a new article published in the Journal of Infectious Diseases is one more example of how the lessons learned in that terrible time continue to guide scientists today.

The 1918 flu struck before the full flowering of modern epidemiology, but the science of tracking and containing disease was certainly more advanced than it had ever been before. Tissue samples were frozen for study, carriers were traced for the source of the contagion and infections were prevented that might have spread the disease wider. The pandemic chastened the U.S. military, which lost 44,000 men to flu during World War I and wanted no such problems during World War II. In 1943, a team of Army scientists jointly led by a Maj. Jonas Salk developed the first flu vaccine — a dozen years before Salk’s polio vaccine. (More on Time.com: Who’s Afraid of the Flu? Not Moms)

Now, old science is benefiting modern researchers again. Investigators with the National Institute of Allergy and Infectious Diseases (NIAID) analyzed 13 scientific papers published about the flu from 1918 to 1920, looking specifically for research into the role pneumonia played in killing influenza victims. At the time, scientists believed flu was caused by a bacterium, not a virus — a belief that was not overturned until British researchers proved the viral link in 1934. During the pandemic, scientists thus tried to develop a bacterial vaccine as a first line of defense against the disease.

The surprise was that this inoculation against the wrong pathogen sometimes helped. Bacterial vaccines are useless against the influenza virus, of course, but they did seem to have been somewhat effective in curbing secondary infections including Streptococcus pneumonia, which are often the proximate cause of a patient’s death. The NIAID thus used contemporary statistical methods to re-crunch the data from the long-ago studies and determine just how well the trial vaccines might have worked. (More on Time.com: Post-H1N1, Why You Still Need to Worry About Flu)

These findings, combined with modern techniques for developing bacterial vaccines, might well be used to help people who miss the basic influenza vaccine and then develop the illness. During last year’s H1N1 epidemic, infections with bacteria are thought to have caused from 29% to 55% of all deaths, suggesting that a lot of needless dying could be avoided in the future. Apparently old science — as long as it’s good science — never fades away.